Electric switch



May 1l,` 1943. E. M. CLAYTQR 2,318,671

ELECTRIC SWITCH Filed April 2, 1941 2 Sheets-Sheet 2 3 5 v5 40 l Asc-mvov 7 a /0/ Y Div/0f INVENTOR ATToRNEYf Patented May 11, 1943 ELECTRICSWITCH Edward M. Claytor, Anderson, Ind., assignor to General MotorsCorporation, Detroit, Mich., a.

corporation of Delaware Application April 2, 1941, Serial No. 386,493

(Cl. Zim- 87) 11 Claims.

This invention relates to speed responsive electrical switches and moreparticularly to air vane switches for use on automotive vehicles forcontrolling certain electrical devices according to the speed of thevehicle.

It is an object of the present invention to provide an air vane switchof economical, durable and compact construction which provides for thequick make and break of its contacts.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Fig. 1 is a plan view of the switch with its cover removed.

Fig. 2 is a sectional view on the line 2-2 of Fig. 1 showing the coverin section.

Fig. 3 is a view of the magnet and armature assembly looking in thedirection of the arrow 3 in Fig. 1.

Fig. 4 is a fragmentary view partly in section looking in the directionof the arrow 4 of Fig. 1.

Fig. 5 is a, sectional view on the line 5--5 of Fig. 1.

Figs. 6, 7, 8, 9 and 10 are wiring diagrams illustrating various uses ofthe air switch.

The switch comprises a circular base 28 to which is attached a bushing2| (Fig. 5) providing the outer race for bearing balls 22, the innerrace of which is provided with a shaft 23 having an enlarged portion 24providing a shoulder 25 which steps down to a portion 26 of lessdiameter. Shaft 23 is provided with a journal portion 21 having abearing in the arm 28 of a bracket 29 having a portion 39 joining theportion 28 with a portion 3| parallel to portion 28, the portion 3|being attached to the base 20. The

shaft 23 extends through a packing member 33 and into a bushing 34fitting on the tapered end of the shaft and clamped by a screw 34a.Bushing 34 provides the hub for a plate 35 shaped to provide an air vane36 and having an arm 31 carrying a weight 38 which, by adding inertia,stabilizes movement of the vane.

The portion 26 of shaft 23 extends through a hole in a plate 40 and thepart 26 is staked against the plate 40 at certain places so that theshaft will drive the plate. Rotation of the shaft 23 in one direction isresisted by a spring 45 coiled around shaft 23 and having one end 46passed through a hole 41 in part 30 of bracket 29 and having the otherend 48 received by one of several notches 49 formed in a flange 50 o1' fthe plate 48. Plate 40 carries studs 5| and 52 either of which mayengage a lug X of an armature to be described. Since the studs 5| and 52are spaced a distance greater than the thickness of the lug X it isevident that a lost motion connection is provided between the plate 40and the lug X. The studs 5| and 52 may be made of Bakelite or Bakelitecoated steel rivets so that the parts touching the lug X arenonconducting.

The base 20 insulatingly supports a bracket 60, there being anonconducting segment 6| interposed between these parts. The bracketwhich is made of magnetizable metal provides an arm 62 to which twoscrews 63 attach a magnetizable resilient armature blade 64 carrying acontact 65 and a magnetizable flux carrying block 66 attached by rivet61 which also secures a conductor strip 68 also secured by the shank ofthe rivet which provides contact 65.

The armature 64 moves relative to a pole face 10 of a core 1| attachedto an arm 12 of the bracket 60 and surrounded by a magnet coil 13attached at one end to the bracket 60 and attached at the other end tothe base 20 in order to provide a ground connection. From the arm 12 ofbracket 60 there extends an ear 15 which is provided with a threadedhole for receiving a terminal screw 16 passing through noncon ductingbushing 11 in a cover 18 in order to secure the cover in position withits flange 19 surrounding the peripheral edge of the base 20 as shownin-Figs. 2 and 5 and with its shoulder portion `in engagement with agasket 8| previously cemented to the base 20. The screw 16 thereforeis aterminal which is common to the armature contact 65 and tothenongroundedendofthecoil13.

. The contact 65 cooperates with av stationary contact xed to an arm 86of a bracket 81 having a partl88 attachedto the base 28 and insulatedtherefrom as shown in Fig. 4. Rivets 88a pass through metal plate 88h,insulating plate 88o, base 20,'insulating plate 6| .and bracket part 88.The bracket 81 has an ear 89 provided with a threaded aperture forreceiving a terminal screw 98 which, like the screw 16, passes through anonconducting bushing 9| attached to the cover 18. The screws 16 and 90therefore provide means for attaching wires to the switch and also forsecuring the cover 18 to the base 20.

The manner of securing the armature sup'- porting and magnet supportingcoil bracket 60 to the base 20 is shown best in Fig. 3. A screw 92passes through a nonconducting bushing 93 which spaces the screw andinsulates it from the bracket 60. The screw 92 passes through theinsulating plate 6|, the base 20, a mounting plate 96 and a washer 94and receives a nut 95. By tightening the nut 95 the bracket 60 and theplate 96 are clamped to the base 20. In a similar manner, plate 96 andbracket 29 are attached to base by a screw 91.

When the spring 45 is arranged as shown in Fig. l, it is biased to causestud 5| to engage armature lug X in order to close the contacts 65 and85 as shown diagrammatically in Fig. 6. Fig. 6 illustrates the use ofthe switch in a circuit including the storage battery and the heatermotor of an automobile. Battery |00 is connected by a switch |0| andwire |02 with terminal 90 of the air switch. Terminal 'I6 is connectedwith the heater motor |02 which is grounded. When the switch |0| isclosed, the heater motor |02 is connected with battery |00 through thecontacts 65 and 85 of the air switch. When a certain vehicle speed ismaintained, it is desirable to `turn olf the motor |02 automatically andthis is accomplished by the separation of the contacts 65 and 85 due tothe pressure of air from the engine cooling fan impinging upon the vane36 as indicated by arrow |03. The separation of contact 65 and thecontact 85 takes place rapidly due to the fact that the pressurerequired to overcome the magnetic pull on the armature is considerablygreater than that required merely to overcome the spring 45. This spring45 is first overcome taking up the lost motionfbetween the armature lugX and the stud 52 on plate 40. The pressure of the air acting upon vane36 tending to rotate it clockwise in Fig. 6 must be great enough notonly to overcome the spring 45 but to overcome the magnetic pullafforded by the magnet coil 13 which is also connected with the batterythrough the contacts 65 and 85. As soon as the pull is overcome thecontacts 65 and 85 separate quickly,'because the instant they separate.the coil 'I3 is deenergized and the plate 40 will then move quicklyagainst stop a, said stop being provided by an ear on bracket 29 asshown in Fig. 1. When the vehicle speed air pressure on vane 36decreases the spring 45 will overcome the air pressure on vane 36, andthe contact 65 will reengage the contact 85. At the instant this occursthe coil I3 will be reexcited and will increase the contact pressurebetween 65 and 85 which is most desirable. In fact the magnetic pullafforded by the electromagnet is great enough to causer the armaturespring 64 to bow slightly so that it will seal against the core. Thebowing of the spring 64 causes a slight rubbing action by the contact 65upon the contact 85 which is desirable in order to keep the contactsclean.

As stated before, the spring shown in Fig. 1 biases the plate 49 intocontact closing position. If a spring 45X shown in Figs. 4 and 5 issubstituted, the plate 40 will be biased into Contact open position,thus holding the contact normally separated from contact 85. The vane 36can be relocated on the shaft 23 so that air pressure will tend to movethe plate 40 into contact closing position as shown in Fig. 7. When theair switch is adapted for making contact under air pressure, it may beused to control some electrical device on the automobile .which isdesirable for use when driving at high speed. In Fig. '7 the switchcloses with a snap action when a certain high speed is reached and openswith a snap action when the speed falls below a predetermined value.

In the installations shown in Figs. 6 and '7 the air switch is providedwith two insulated terminals i6 and 99. This requires that two wireslead from the switch (which is usually located near the front end of theengine under the hood) to the battery and to the heater motor or otherelectrical accessory. Figs. 8 and 9 show installations similar to Figs.6 and 7, respectively, except that only one Wire connected with switchterminal 99 is required. The heater motor |02 in Fig. 8 or theelectrical device |05 in Fig. 9 is provided with two insulated terminalsconnected, respectively, with the control switch 0| and with terminal 96of the air switch. In the installations shown in Figs. 8 and 9, thecircuit of the motor or electrical device includes not only the contactsof the air switch, but the magnet winding 'i3 as well. Therefore themagnet winding 'I3 should be of low resistance so as not substantiallyto reduce the voltage impressed upon the current consuming device. Fig.l0 shows an installation in which the heater motor |02 is connected witha battery ground circuit through a switch ||0 which is normally closedexcept when the transmission gears are in high or third speed. Theheater motor will operate when the switch |6| is closed in low andintermediate speed regardless of the status of the air switch. When thetransmission is in high or third speed, switch H9 is automaticallyopened by means not shown; therefore the air switch controls thestopping of the heater motor when a certain high speed is obtained andrestores its operation again when the speed drops back to some lowervalue.

From the foregoing description ofthe construction of the air switch andthe various Ways in which it may be installed, it is apparent that theair switch can easily be adjusted for normally closed contacts opened byair pressure or norrnally opened contacts closed by air pressure. Whileit is provided with two terminals, it is adapted for use in a circuitwhere only one of its terminals (terminal is required, the circuit beingoompleted when the switch contacts are closed and through the groundedmagnet coil of the switch which is used to effect increase of contactpressure when the contacts close and to cause a build-up in operatingforces so that the contacts open quickly when the opening force becomeseective.

The armature 64 and parts supported thereby divide the switchcompartment into two parts. The par-t to the left of armature 64(Fig. 1) is occupied by shaft 23, bracket 29 and biasing spring 45 or45X. The part to the right of armature 64 is occupied by bracket 6magnet core 1| magnet coil 'F3 and by bracket 81. The space within thecase 'I8 is therefore used to the best advantage. For automobile use,the switch can be made small and compact. In fact the switch is muchsmaller than shown in the patent drawings.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

l. An electric switch having a magnetizable resilient amature bladecarrying a contact, a stationary contact engaged thereby and connectedwith a terminal, means for controlling the position of the blade withrespect to its contact mak ing-and-breaking status, and electromagneticmeans for retaining the blade in contact making' position and includinga magnet coil, a core, a-

magnetizable bracket supporting the core and one end of the amatureblade;and a flux carrying, block attached to the armature near its xedend.

and on the side thereof remote from the core;

thus permitting the armature blade to seal against attached to the base;a flexible armature extend.`

ing between the shaft and the brackets, said amature having one Aendfixed to one of the brackets and having its free end provided with acontact for engagement with a stationary contact carried by the otherbracket, at least one of the contacts having a convex surface; a platefixed to the shaft and having provisions cooperat- Y ing with thearmature to open and close the contacts; an eleotromagnet for attractingthe armature and including a magnet coil and a core carried by thebracket to which the armature is attached; a flux carrying blockattached to the flexible armature and on the side remote from the coreface, thus permitting the armature to bend toward the core face so as tochange the relation of the contacting surfaces of the contacts when themagnet coil is energized.

3. An electric switch comprising in combination; a base; a shaftjournalled in a bearing provided by the base, said shaft being locatedon one side of a medial line of the base: a pair of mounting bracketsattached to the base on the other side of the medial line of the base; aflexible armature extending substantially along the medial line andhaving one end secured to one of the brackets and having its free endprovided withy a contact adapted to engage a stationary contact xed tothe other mounting bracket, at least one of the contacts having a convexsurface; means fixed to the shaft and operable upon the amature to openand close the contacts; electromagnetic means for attracting theflexible armature in contact making position and including a magnetcoil, and a core carried by the bracket supporting .the armature; a fluxcarrying block attached to the armature and on the side remote from thecore and thereby permitting the armature to bend and seal against theface of the core so as to shift the engaging portion of the contactswhen the magnet coil is energized. f

4. An electric switch comprising in combination; a base; a shaftjournalled in a bearing provided by the base and in a bearing spacedfrom the base and supported by a bracket attached to the base, saidshaft being located on one side of a medial line of the base; a pair ofmounting brackets attached to the base on the other side of the medialline; a flexible armature extending substantially along the medial lineand having one end secured to one of the mounting brackets and havingits free end provided with a contact adapted to enga-ge a stationarycontact fixed to the other mounting bracket, said other mounting bracketsupporting an electromagnet having a coil connected with the armature; aflux carrying block carried by the armature and on the side remote fromthe core of the electromagnet whereby the flexible armature will bendwhen the magnet coil is energized causing the movable contact to slideover the face of the stationary contact.

5. An electric switch comprising in combination; a base; a bearingcarried by the base on one side of a medial line; a support having aflange provided with a bearing in alignment with the base bearing; anactuating shaft journailed in the bearings; a pair of mounting bracketssupported by the base on the other side of the medial line; a resilientarmature extending substantiallyalong the medial line and fixed at oneend to one of the mounting brackets and carrying a contact at its freeend adapted to engage normally a stationary contact carried by the firstmentioned bracket having a coil connected with the armature; means foractuating the shaft in one direction of rotation; a drive plate movablewith Ithe shaft for moving the armature to separate the contacts;yieldable means for resisting the movement of the shaft in said onedirection and operating to move the shaft through the drive plate in theopposite direction as the shaft actuating means is reduced; an enclosurefor the base, support and the brackets; and means for securing theenclosure to the brackets, said securing means operating as terminalsfor the switch.

6. An electric switch comprising, a base and a cover providing acompartment; a mounting bracket of magnetizable metal supported from thebase; a resilient armature blade extending across the compartment andfixed at one end to the mounting bracket and carrying a contact at theother end; armature retaining means in the compartment on one side ofthe armature, said retaining means comprising an electromagnet having acore extending from the bracket and y having a coil connected with thearmature; a support on the same side of the armature with the magnet andcarrying a contact engageable with the armature contact and providingaterminal for the switch; a magnetizable plate secured to the armaturenear its fixed end, thus permitting the armature to seal against thepole face of the core and permitting the armature portion projectingbeyond the magnetizing plate to bend and thereby produce a wiping actionbetween the contacts when the electromagnet is energized; and meansjournalled in the base and on the other side of the armature forcontrolling the position of the armature.

7. An electric switch comprising, a base and a cover providing acompartment; a mounting bracket of magnetizable metal supported from thebase; a resilient armature blade extending about midway across thecompartment and ilxed at one end to the mounting bracket and carrying acontact at its free end; armature retaining means in the compartmentV onone side of the armature, said retaining means comprising anelectromagnet having a core extending from the bracket and having a coilvconnected with the armature; a support on the same side of the armaturewith the magnet and carrying a contact engageable with the armaturecontact and providing a terminal for the'switch; a magnetizable platesecured to the armature near its fixed end, thus permitting the armatureto seal against the pole face of the core and permitting the armatureportion projecting beyond the plate to bend to produce a wiping actionbetween the contacts when the electromagnet is energized; and means forcontrolling the position of the armature, said means including a shaftjournalled in the base: means for actuating the shaft in one directionof rotation; means carried by the shaft for 'transmitting motion fromvthe shaft to the armature; and resilient means engaging said shaftcarrying vmeans so as to apply a force to said carrying means inopposition to .said actuating means.

8. An electric switch comprising, a base and a cover providing acompartment; a mounting bracket of magnetizable metal supported from thebase; a resilient armature blade extending about midway across thecompartment and fixed at one end to the mounting bracket and carrying acontact at the other end; armature retaining means in the compartment onone side of the armature, said retaining means comprising anelectromagnet having a Vcore extending fromA the bracket and having acoil connected with the armature; a support on the same side of thearmature with the magnet and carrying a contact engageable with thearmature contact and providing a terminal for theswitch; a magnetizableplate of lesser dimension than vthe armature secured to the armature-ina manner to permit-'the armature tobend and produce a wiping actionbetween the contacts when the electromagnet is energized; a shaftjournalled in the base; nuid actua-ted means for rotating the shaft inone di; rection or" rotation; a plate carried by the shaft having'provisions for operating the armature; and Aisp'ring means cooperatingwith the plate for resisting movement of the shaft in said onedirectionand operating to move the shaft in the opposite direction asthe fluid actuated means is reduced. 9. A switch of the type describedcomprising,

a support, a shaft rotatably carried by the sup'- port; a pair'of'spaced abutments movable with thefshaft; a fiexible armature havingone end x'ed relative to the support and having its free end sopositioned that it will be located between the abutments; normallyspaced contacts, one of said contacts being movable with the armature;spring means for `urging the shaft in one direction whereby one of theabutments engages the armature to hold normally the movable contacts outoff engagement with the other contact; fluid means for rotating theshaft in the opposite direction and causing the other abutment to biasthe armature to urge the movable contact into engagement with the othercontact; an 'electromagnet having a coil electrically 'connected withone of the contacts; anda iiux carrying member carried by the armatureand so arranged with respect thereto to permit the nexible armature tobend upon energization of the coil so as to change the relation of thecontacting `surfaces of the contacts.

10. An electric switch comprising in combination; Va rotatable shaft;fluid actuated means for the shaft; a flexible armature having one endfixed and having a contact at the other end; a stationary contact; anelectromagnet including a core and a winding; an energizing circuit forl' the winding including said contacts; means movable with the shaft tobend the armature and move its contact into engagement with thestationary contact causing the winding to be energzed whereby the magnetcore will exert ia force to distort the armature and thereby causethearmature contactto shift the point of engagement; means foractuating-the shaft in one direction; and -resilient means for resistingmovement of the shaft in said one direction.

11. `An electric switch comprising in combination; a rotatable shaft;fluid actuating` means for the shaft; a iiexible armature having one endfixed and having a contact at the other end; a stationary contact; anelectromagnet including a core and a winding; an energizing circuit forsaid winding including said contacts; devices on opposite sides of thearmature and movable With the shaft, one of said devices operating tomove the armature contact into engagement with the stationary .Contactwhen the shaft is rotated in one direction by the fluid actuated meanscausing the winding to be energized whereby the magnet core will exert aforce to distort the armature and causing the armature contact to slideover the stationary contact to change the point of engagement; springmeans for resisting. the movement of theshaft, said spring meansoperating to rotate the shaft in the opposite direction as the iiuidactuating means is reduced to cause the other device to move thearmature and separate the contacts.

EDWARD M. CLAYTOR.

